Explanation:

• The Darjiling and Sikkim Himalayas are flanked by Nepal Himalayas in the west and Bhutan Himalayas in the east. It is relatively small but is the most significant part of the Himalayas.
• Known for its fast-flowing rivers such as the Tista, it is a region of high mountain peaks like Kanchenjunga (Kanchengiri), and deep valleys.
• The higher reaches of this region are inhabited by Lepcha tribes while the southern part, particularly the Darjiling Himalayas, has a mixed population of Nepalis, Bengalis and tribals from Central India.
• The British, taking advantage of the physical conditions such as moderate slope, thick soil cover with high organic content, well distributed rainfall throughout the year and mild winters, introduced tea plantations in this region.
• As compared to the other sections of the Himalayas, these along with the Arunachal Himalayas are conspicuous by the absence of the Shiwalik formations.
• In place of the Shiwaliks here, the ‘duar formations’ are important, which have also been used for the development of tea gardens.

Source: Class 11^th NCERT